From what I can tell, the upper time limit for magnetic media is generally expected to be 30 years[1]. My money is on survivorship bias for longer time frames.

From what I can tell, the upper time limit for magnetic media is generally expected to be 30 years[1]. My money is on survivorship bias for longer time frames. I've had 5 1/4" and 3 1/2" floppies die on me within months of purchase - I don't recall that ever happening for a CD/DVD, but I'm sure someone has had that experience. Anecdotes aren't hard data, but I have 2 CD binders full of CDs and DVDs that have outlasted 3 hard drives that I didn't keep backed up as a young adult, and as long as they were kept away from scratches and heat, all of them were easily read and playable. [1] https://www.clir.org/pubs/reports/pub54/4life_expectancy https://www.clir.org/pubs/reports/pub54/4life_expectancy